"True, non-violent sexual advance doesn't distinguish between homosexual or heterosexual advance - but in practice, recent cases suggest it's only being used in the context of homosexuality. In other words, 'gay panic'."

Signatures soared after British comedian Stephen Fry re-tweeted a link to the campaign to his 3.7 million followers on Twitter, and popular fantasy writer Neil Gaiman has also urged his 1.7 million Twitter followers to sign.

To sign the petition, visit change.org and search for "homosexual advance".